Abstract: A digital watch has a fluorescent display which is selectively actuated by depressing a button which extends through the watch casing. The watch crystal is formed from a scratch resistant mineral glass, and has a thin film mercury coating on the inner surface. The mercury coating may be sandwiched between the watch crystal and a thin transparent plastic film. When the fluorescent display is activated the display may be seen by the outside world through the watch crystal. However, when the fluorescent display is inactivated, the watch crystal appears as a mirror to the outside world. In a second embodiment of the invention, a tinted watch crystal is utilized in conjunction with a fluorescent display.